Characterization of a DNA sequence family in the Prader-Willi/Angelman syndrome chromosome region in 15q11-q13.

IR4-3R (D15S11) is an anonymous DNA sequence from human chromosome 15. Using YAC cloning and restriction enzyme analysis, we have found that IR4-3R detects five related DNA sequences, which are spread over 700 kb within the Prader-Willi/Angelman syndrome chromosome region in 15q11-q13. The RsaI and StyI polymorphisms, which were described previously, are associated with the most proximal copy of IR4-3R and are in strong linkage disequilibrium. IR4-3R represents the third DNA sequence family that has been identified in 15q11-q13.